Adjustable gastric banding apparatus have provided an effective and substantially less invasive alternative to gastric bypass surgery and other conventional surgical weight loss procedures. Unlike gastric bypass procedures, gastric band apparatus implantations are reversible and require no permanent modification to the gastrointestinal tract. Moreover, it has been recognized that sustained weight loss can be achieved through a laparoscopically-placed gastric band, for example, the LAP-BAND® (Allergan, Inc., Irvine, Calif.) gastric band or the LAP-BAND AP® (Allergan, Inc., Irvine, Calif.) gastric band. Generally, gastric bands are placed about the cardia, or upper portion, of a patient's stomach forming a stoma that restricts food's passage into a lower portion of the stomach. When the stoma is of an appropriate size that is restricted by a gastric band, food held in the upper portion of the stomach may provide a feeling of satiety or fullness that discourages overeating. An example of a gastric banding system is disclosed in Roslin, et al., U.S. Patent Pub. No. 2006/0235448, the entire disclosure of which is incorporated herein by this specific reference.
Over time, a stoma created by a gastric band may need adjustment in order to maintain an appropriate size, which is neither too restrictive nor too passive. Accordingly, prior art gastric band systems provide a subcutaneous fluid injection port connected to an expandable or inflatable portion of the gastric band. By adding fluid to or removing fluid from the inflatable portion by means of a hypodermic needle inserted into the access port, the effective size of the gastric band can be adjusted to provide a tighter or looser constriction.
However, medical professionals frequently encounter difficulty with the process of targeting the injection port, including problems with locating the access port, determining the appropriate angle at which the needle should penetrate the access port, and determining whether the needle has sufficiently penetrated the access port.
Some attempts have been made to overcome these difficulties. For example, with reference to FIG. 1A, the Heliogast® EV3 implantantable port (“EV3 port”) may allow needle penetration at a portion A of the EV3 port. However, the surface area of portion A constitutes only a fraction of the surface area of the entire outer surface of the EV3 port. In addition, the EV3 port still requires very precise needle insertion angles and locations such that they are in a discrete septum, as shown in FIG. 1B, and cannot facilitate a directionless or virtually directionless needle injection port, as shown in FIG. 1C. Indeed, FIG. 1C appears to illustrate that the EV3 port requires that needle insertions be orthogonal to the surface.